import * as THREE from "three";
// 导入轨道控制器
import { OrbitControls } from "three/examples/jsm/controls/OrbitControls";
// 导入动画库
import gsap from "gsap";
// 导入dat.gui
import * as dat from "dat.gui";

const scene = new THREE.Scene();

// 2、创建相机
const camera = new THREE.PerspectiveCamera(
  75,
  window.innerWidth / window.innerHeight,
  0.1,
  1000
);

// 设置相机位置
camera.position.set(0, 0, 10);
scene.add(camera);

const particlesGeometry = new THREE.BufferGeometry();
const count = 5000;

// 设置缓冲区数组
const positions = new Float32Array(count * 3);
// 设置粒子顶点颜色
const colors = new Float32Array(count * 3);
// 设置顶点
for (let i = 0; i < count * 3; i++) {
  // 顶点位置 随机 -50 到 50
  positions[i] = (Math.random() - 0.5) * 100;
  colors[i] = Math.random();
}
particlesGeometry.setAttribute(
  "position",
  new THREE.BufferAttribute(positions, 3)
);
particlesGeometry.setAttribute("color", new THREE.BufferAttribute(colors, 3));

// 设置点材质
const pointsMaterial = new THREE.PointsMaterial();
pointsMaterial.size = 0.5;
// pointsMaterial.color.set(0xfff000);
// 相机深度而衰减
pointsMaterial.sizeAttenuation = true;

// 载入纹理
const textureLoader = new THREE.TextureLoader();
const texture = textureLoader.load("./textures/particles/9.png");
// 设置点材质纹理
pointsMaterial.map = texture;
// 设置点材质贴图透明
pointsMaterial.alphaMap = texture;
// 设置点材质透明
pointsMaterial.transparent = true;
// 关闭深度写入 不重叠
pointsMaterial.depthWrite = false;
// 设置混合模式
pointsMaterial.blending = THREE.AdditiveBlending;
// 设置启动顶点颜色
pointsMaterial.vertexColors = true;

const points = new THREE.Points(particlesGeometry, pointsMaterial);

scene.add(points);

// 初始化渲染器
const renderer = new THREE.WebGLRenderer();
// 设置渲染的尺寸大小
renderer.setSize(window.innerWidth, window.innerHeight);
// 开启场景中的阴影贴图
renderer.shadowMap.enabled = true;
renderer.physicallyCorrectLights = true;
// 将webgl渲染的canvas内容添加到body
document.body.appendChild(renderer.domElement);

// 创建轨道控制器
const controls = new OrbitControls(camera, renderer.domElement);
// 设置控制器阻尼，让控制器更有真实效果,必须在动画循环里调用.update()。
controls.enableDamping = true;

// 添加坐标轴辅助器
const axesHelper = new THREE.AxesHelper(5);
scene.add(axesHelper);
function render() {
  controls.update();
  renderer.render(scene, camera);
  //   渲染下一帧的时候就会调用render函数
  requestAnimationFrame(render);
}

render();

// 监听画面变化，更新渲染画面
window.addEventListener("resize", () => {
  //   console.log("画面变化了");
  // 更新摄像头
  camera.aspect = window.innerWidth / window.innerHeight;
  //   更新摄像机的投影矩阵
  camera.updateProjectionMatrix();

  //   更新渲染器
  renderer.setSize(window.innerWidth, window.innerHeight);
  //   设置渲染器的像素比
  renderer.setPixelRatio(window.devicePixelRatio);
});
